Sheet feed apparatus



Aug.

7*, 1962 G. sPn-:ss

SHEET FEED APPARATUS Filed Dec. 15, 1959 llilll 1| ll llilllllm United States aten-t 3,048,391 SHEET FEED APPARATUS Georg Spiess, 9 Possartstrasse, Munich, Germany Filed Dec. 15, 1959, Ser. No. 859,807 Claims priority, application Germany Dec. 15, 1958 1 Claim. (Cl. 271-26) 'I'his invention relates :to sheet feed apparatus having separating and lifting suckers of telescopic form, of which at least two are disposed near the rear edge of the stack `from which sheets are to be fed one at a time. The practice of arranging the separating `and lifting suckers on such sheetafeed appliances so that their 4axes are not aligned in a `strictly vertical position to the surface of the stack, but are inclined somewhat out of the vertical towards the centre of the stack, is already known. 'Ihe purpose of this slight inclination is to achieve tautness in the part of the uppermost sheet between the two lifting suckers or suction lgrippers so that a feeler, arranged between the suckers, does not touch the sheet which has just been picked up, when it is placed on the stack.

In practice, however, it is found that this oblique arrangement of the lifting suckers may interfere with smooth running when thick paper or card is being handled. Owing to the stiffness of the sheet material, it may happen that the inclined lifting suckers are not raised quite to their topmost positions, because the part of the sheet held between them does not yield sufficiently. In order to eliminate this disadvantage, the present invention provides `for the telescopically arranged separating and lifting suckers to be supported in such a way that their angle of inclination out of the vertical is adjustable, preferably within a range of about six to zero degrees to the vertical.

Such adjustment may be arranged in various ways from the point of view of design, `whilst ensuring air tightness of the vacuum connections to the lifting suckers. ln one possible form of the invention, a vacuum con nection tube to the respective sucker at each side is supported inl a projecting arm having a cylindrically turned end supported free to rotate in a suitable socket in a bracket fixed to the main vacuum tube, so as to constitute pivoting axis for the respective sucker. The cylindrically turned end of the projecting arm may be pressed in an airtight manner against the edge of the bracket by means of a lfixing screw inserted axially therein. It may also be desirable for the angular adjustment of the lifting sucker to be limited in both directions by stops.

The invention will be described further, by way of example, with reference to the accompanying drawings which illustrate one practical embodiment, and wherein:

FIG. l is an elevation of the device as viewed from the rear of the stack of sheets to be fed;

FIG. 2 is a view similar to FIG. 1 but showing the suckers in inclined positions, and Y FIG. 3 is a cross-section taken on the line III-III of FIG. 1.

The arrangement comprises lifting suckers 1 and 2, of known telescopic form, which are situated at the two 3,948,391 Patented Aug. 7, 1962 connecting pipe 6 leading from the respective sucker.

1 or 2 being `secured into the ar-m 5. A screw 7 has its threaded portion 8 inserted into an axial threaded hole at the end of the projecting arm remote from the pipe 6 in such a way that the head of the screw 7 is in contact with a washer 9 which overlaps the bracket 4. AS a result of this arrangement, the projecting arm 5, together with the lifting sucker can be rotated (when the screw 7 is loosened) around the axis 11 (shown as a dot-and-dash line) of the socket of bracket 4 and can be tixed in any position by tightening the screw 7. When this screw 7 is tightened, the confronting sealing surfaces 10 between the bracket 4 .and arm 5 are pressed tightly together, a packing ring (not shown) being arranged between them if necessary. On the outside of the projecting arm 5 is a peg 12 which lies between two stops 13 on the outside of the bracket 4 and thus limits the angle of adjustment of the lifting sucker round the axis 11 in both directions, by its contact with these stops. In addition, the lifting sucker is adjustable in known manner so far as its position is concerned in the direction of feed of the sheets, by pivoting round the' axis ofthe vacuum connecting pipe 6.

For the sake of simplicity, the `feeler is not shown in the drawing. This feeler lies on the rear edge of the stack 15, approximately in the position marked by the reference numeral 14.

l claim:

A device for use in a sheet feeder for lifting successive sheets from a pile of sheets, comprising a vacuum tube support extending transversely of said pile, a bracket mounted on either end of said support and an elongated socket having a passage therein connected to each of said brackets and rotatable therein and adapted to engage a pipe, said pipe being rotatable with the bracket and connected to said vacuum tube through said bracket, a suction gripper depending Ifrom :the end of each of said pipes, said suction grippers adapted to be moved from a normal vertical position towards each other, and a pin and stop assembly mounted on each of said brackets for limiting the movement thereof, and screw means connected to the socket for locking said suction grippers in the -adjusted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,433,423 Stevens Oct. 24, 1922 2,869,867 Backhouse Jan. 20, 1959 2,941,799 Reincke .Tune 21, 1960 2,950,913 Staines Aug. 30, 1960 FOREIGN PATENTS 412,015 Germany Apr. 8, 1925 674,844 Great Britain July 2, 1952 

